Vibratory finishing apparatus



Dec. 23, 1969 R cK|BBEN ET AL 3,484,998

VIBRATORY FINISHING APPARATUS Original Filed April 17, 196'? 3 Sheets-Sheet 1 1969 R. K. M KIBBEN ET AL 3,484,998

VIBRATORY FTIIISIIIIIG APPARATUS Original Filed April 17, 1967 3 Sheets-Sheet 2 M i a Z rm war I KPAMJ 1 F m .2 A M A w my; 6 Z M w flnnnn w =m 6 ,u z n \X\\\\\\\vK\\\\\\ A 5 W 5 BY; 4% v ATfEA/-V R. K. M KIBBEN ET AL 3,484,998

VIBRATOHY FINISHING APPARATUS Dec. 23, 1969 5 SheetsShe et 5 Original Filed April 17,

I N V-EN TORS.

United States Patent 3,484,998 VIBRATORY FINISHING APPARATUS Richard K. McKibben, La Canada, Bill A. Racine, Ha-

cienda Heights, and John R. Strom, Fullerton, Calif.,

assignors to SWECO, Inc., Los Angeles, Calif., a corporation of California Continuation of application Ser. No. 631,471, Apr. 17, 1967. This application Mar. 10, 1969, Ser. No. 809,463 Int. Cl. B24b 57/00 US. Cl. 51-163 8 Claims ABSTRACT OF- THE DISCLOSURE This application is a continuation of Ser. No. 631,471 filed Apr. 17, 1967 now abandoned.

This invention relates to vibratory grinding, finishing and deburring mills in which a material to be operated on p is contacted with a finishing or grinding media in a vibrating environment. More particularly, this application relates to a toroidal bowl vibratory finishing mill having a vertical dam or weir which is movably mounted in the toroid and means for insuring that the weir will form a relatively water tight seal and yet will easily move within the mill chamber.

Toroidal bowl vibratory finishing vessels in which a charge of relatively abrasive media is caused to operate on a part to be finished are known in the art and illustrated, for example, by US. Patents 3,100,008; 3,266,739 and 2,268,177. It has been suggested to interpose a vertical dam or weir across a radius of the finishing chamber to both control the motion of parts and media in the mill and to aid in the discharge of parts and media by elevating them to an upper portion of the mill. This concept is disclosed in a patent application filed concurrently with the present application in the name of John R. Strom which application is based in part on an application made in Great Britain on May 4, 1966, bearing Application Serial No. 19653/ 66 and entitled Vertical Dam.

In the design of a vertical dam or weir for use in conjunction with the toroidal bowl, it is desirable to make provision for the weir or dam to retract out of position through the bottom portion of the mill chamber; thus creating a sealing problem of the mill chamber by virtue of the fact that liquids are often employed in the finishing operation.

Furthermore, it has been found in practice that moving the vertical weir upward and downward becomes increasingly difiicult after the mill is in operation because, during the finishing operation, fine particles of degraded media andmaterial removed from the parts being finished tend to clog any channel or trackway which is provided for guiding the movement of the weir.

3,484,998 Patented Dec. 23, 1969 It is therefore an object of this invention to provide a vertical weir configuration in a toroidal bowl finishing mill which allows the weir to be readily moved upward and downward in the mill.

It is another object of this invention to provide a means for positively sealing a vertical weir in a toroidal bowl finishing mill during the finishing and unloading operation.

In the drawings accompanying this specification, FIG- URE 1 is an overall view in cross section of a mill embodying the invention;

FIGURE 2 is a partial plan view, partially in phantom, of a toroidal bowl finishing mill having a vertical weir;

FIGURE 3 is a cross section through the line 33 of FIGURE 2 showing the leading edge of the vertical weir Il'l cross section;

FIGURE 4 is an enlarged cross section view of the device taken along the line 4-4 in FIGURE 3, in partial cutaway;

FIGURE 5 is an exploded view of the weir and mountin g and retaining means therefor;

FIGURE 6 is a cross section of the mill sealing means and weir taken through the line 66 in FIGURE 3;

FIGURE 7 is a cross section view of the weir and its sealing means taken through the line 77 of FIGURE 3;

FIGURE 8 is a cross section taken through the line 88 of FIGURE 5; and

FIGURE 9 is a view illustrating the construction detail of the lip seal generally in accordance with FIGURE 7.

According to the present invention there is provided a vibratory finishing apparatus having a generally toroidal finishing bowl in which a charge of parts to be finished and a finishing media are subject to vibration and in which a vertical weir or dam may be provided to aid in controlling both the motion of the charge and unloading and separating the parts, the weir being sealed against the resilient lining of the mill by provision of a resilient lip seal on the side wall and bottom of the apparatus.

Referring now to FIGURE 1, there is illustrated a toroidal bowl finishing mill which consists of a circular base 101 having a lip 102 projecting from the upper portion thereof. Around the lip are mounted -a ring of springs 103. Supported on the ring of springs 103, is the toroidal finishing bowl assembly which has a lower donut-shaped supporting plate 104 which is attachedto the ring of springs and a generally circular center column 105 which projects below the lower plate 104 to form a well for attachment of the motor 106. Gusset plates 107 are formed to support the entire assembly and center column and are positioned between the springs. The toroidal chamber 108 is formed by the upper portion'ofthe center column side wall 105, the base plate 104and the upper portion of the outer side wall 109. The toroidal chamber is lined, as shown at 110, with a suitable resilient material such as hard rubber or polyurethane. The motor is supported in the center column by support rings and a clamp assembly as shown generally at 111, and has upper and lower eccentric weights 112 and 113 attached to either end of the vertical motor shaft. The center column may be provided with a cover 114 which may be affixed to a cylindrical projection 115 of the center column 105. Located across a radius of the toroidal chamber 108 is a verticaldam or weir 116 which, as illustrated, projects below the upper extremity of the lining 110. The weir is retractable through the bottom of the lower mill plate 104 and the lining 110 by an appropriate slot and is arranged to be raised and lowered in the slot by one or more air cylinders 117 and their associated pistons 118. The upper end of the piston 118 is afiixed to the upper surface 119, as illustrated, by the flange 120. The weir 116 is hollow so that when the pistons 118 are retracted into the air cylinder 117, the weir moves downward and covers a portion of the air cylinders 117. The notched portion 121 is to allow the weir to retract to cover the air cylinder support structure 122 so that when the weir 116 is fully retracted, it is approximately level with the bottom mill lining 110. During ordinary finishing operations, the weir 116 is held below its maximum upper level and may be as low as flush with the bottom portion of the mill. When the finishing cycle is completed, air under pressure may be applied to the air inlet hose 123 to force the pistons 118 upwardly so that the weir moves to its uppermost position in the chamber. The height of the weir 116 at its uppermost portion may be controlled by the bracket and stop arrangement 124 and the depending adjustable bracket and lug 125. When the weir is in its uppermost position, the parts and media are caused to climb up the upstream side of the weir and fall onto a screen so that the parts may be separated from the media, the media falling back into the chamber 108 while the finished parts are removed from the apparatus.

In FIGURE 2. the toroidal bowl 10 of a finishing mill is illustrated partially in phantom, the inner circle 11 of the drawing indicating the center column. The exterior wall 12 and interior wall 13 are preferably of metallic construction and are lined on their interior surfaces 14 and 15 with a non-abrasive, non-metallic material such as hard rubber, or, preferably, polyurethane. The interior lining 15 is generally'arcuate and follows the circular configuration of the interior wall 13 throughout the diameter thereof except for that portion in the neighborhood of the vertical weir or dam 16. In order to facilitate the vertical upward and downward movement of the weir 16, relatively flat depressed portions 17 and 18 are provided on the linings 14 and 15. As with the interior lining 15, the outer lining 14 follows the curvature of the outer wall 12 except in the portions immediately adjacent and including the weir 16. The flat portions 17 and 18 of the linings 14 and 15 are provided to reduce binding which might be caused by the movement of the weir 16. It is necessary that the weir move freely up and down in the chamber 19 created by the inner and outer walls 12 and 13 and thecurved or flat bottom of the mill (not shown). In practice, the weir 16 is retractable through an opening provided in the mill bottom and, when the mill is being operated ina finishing cycle, the weir is either partially'or totally retracted to below its maximum height. Because the mill is ordinarily charged with an aqueous finishing liquid in addition to the parts and media being processed, it is necessary that the ends of the dam 16 immediately adjacent the linings 14 and 15 seal positively to prevent the flow of liquid through the bottom opening, and as indicated above, still be freely movable to any desired position vertically in the mill.

When the mill is in operation, the vibratory forces of the eccentric weight motors used to energize the mill cause movement of the mass in themill in two separate and superimposed patterns. One of the these modes of motion causes charge of parts and media to climb up the outer lining 14 and rollinward toward the center wall 13. The other mode of motion causes the entire mass of parts. and media to move generally in the direction of the arrow 20 toward the upstream side 21 of the weir 16. Thus, a considerable force is exerted against the weir and provision must be made to positively retain the weir 16 in, its vertical upright position so that it will not bind against ,the opening in the bottom of the mill through which it projects. This is accomplished by having the 4 weir 16 ride in the depressed portions 17 and 18 of the lining which form retaining surfaces for the weir and seal to be described below.

In one embodiment of the toroidal bowl mill which is not illustrated in overall view, the bottom of the bowl begins at a low point and ascends in a helical path around the chamber so that there is a sudden transition point from the upper to the lower portion of the bottom. When a vertical weir is employed, it is ordinarily insertable into the mill chamber 19 at the transition point or high point. Thus, the bottom of the chamber 19 would be higher at 22 and lower at 23; i.e., the weir 16 divides the chamber at the transition point. In making the transition up the helical path, the curvature of the bottom of the bowl increases toward the high portion 22 and is more nearly rectangular at the lower portion 23, there being a gradual transition around the chamber 19.

Referring now to FIGURE 3, there is shown a vertical cross-section of the weir through the line 33 in FIG- URE 2 which is taken partially at the leading or downstream edge of the weir 16. In FIGURE 3, the dashed line 30 represents the arcuate bottom of the lining of the finishing chamber 19 behind the weir in the area 22 when the weir is raised to its uppermost vertical position. The line 33 represents the curvature of the chamber 19 on the downstream side of the weir 16. The weir 16 is thus in position between the more arcuate portion or upstream portion of the mill and the less arcuate or downstream portion of the mill.

The weir 16 has a horizontally extending upper surface 31 and the lower portion of the weir extends below the bottom 30 of the toroidal bowl and provision may be made as indicated by the broken away shafts 32 for moving the weir up and down by means of air cylinders.

Some of the details of the mounting of the Weir and the seal arrangement of this invention are illustrated in FIG- URE 4 which is a cross section taken through the line 44 of FIGURE 3. The weir 16 is shown riding against the flat, depressed portions 17 and 18 of the mill linings 14 and 15. On the downstream side of the weir is an inserted U-shaped sealing bracket 40 which has upwardly projecting legs 41 and 42 which gradually increase in thickness toward the bottom, generally in accordance with the line 33 of FIGURE 3. At the edge of the bracket 40, closest to the weir 16, is the lip seal 43. On the upstream side of the weir 16 there is a U-shaped sealing bracket 44 having outwardly projecting flanges 45 for mounting on the top of the mill linings 14 and 15. Around the entire inner periphery of the bracket 44 is a second lip seal 46.

FIGURE 5 is an exploded view in perspective of the channel arrangements shown in FIGURES 3 and 4 illustrating the relative positions of the weir 16, bracket 40, bracket 41 and the mill linings 14 and 15. FIGURE 5 illustrates the manner of mounting the bracket 41 through the flanges 45 and the bolt hole 51. It also illustrates a method of mounting the bracket 41 in the bottom of the mill lining through the partially shown bolts 52. Similarly, bolt holes 53 may be located on the upward porjections of the U-shaped bracket 40 and the bracket 40 may be provided for bottom bolts 54 for attaching to the bottom of the mill lining. FIGURE 5 likewise shows the lip seal 46 which extends along the entire inner periphery of the downstream portion of the bracket 44 and the lip seal 43 on the lower portion of the bracket 40. In an alternative embodiment of the invention, the lip seal 43 may extend the entire inner periphery of the U- shaped bracket 40. p

The cross sectional detail of the weir 17 and a portion. of the upstream lip seal 46 are illustrated in FIGURE 6, which indicates the center portion of the weir 16 fabricated from a metallic channel 61 such as aluminum which is preferably coated by a resilient material such as polyurethane as shown at 62. As illustrated at 63, there is a small clearance between the mill lining 14 and the poly urethane coating 62 of the weir. The clearance 63 is to enable the weir 16 to move up and down without binding in the event that small particles of degraded media and material removed from the parts being finished become lodged between the weir 16 and mill lining 14..The clearance 63 also serves to accommodateany relative expansion and contraction between the weir coating 62 and the mill lining 14.

FIGURE 6 also illustrates the lip seal 43 on the downstream bracket 40 and illustrates that the upwardly projecting leg 42 narrows as it projects toward its upper surface 64.

The lowermost portion of the weir andlip, seal assembly is shown in cross section in FIGURE 7 which is taken through the line 7-7 of FIGURE 3. The upstream and downstream brackets 44 and 40 are illustrated as being,

attached to the mill lining through bolts 54 and 52. The bracket portion forming the downstream lip seal 43 is shown to be approximately level at its outer extremity with the bottom portion of the mill lining 71. The bracket forms a depression 72 toward the lip seal 43 and then projects upwardly toward the weir 16 to form a positive seal. The interior side 72 projects diagonally upward toward the Weir 16 to provide clearance for moving the weir up and down. The upper surface of the sealing arrangement, therefore, becomes an arcuate concave surface which provides the resiliency required for a positive wiping seal against the weir 16. This arrangement also prevents small parts and media from becoming lodged in the area of the seal when the weir 16 is in its lowermost position. It has been found that when the upper surface of the bottom portion of the seal raises appreciably above the bottom mill lining level, parts and media tend to become locked and motion of the mill during finishing is affected by virtue of the mass having to flow over a hump in the mill bottom. Similarly, the lip seal 46 associated with the upstream bracket 44 has a depressed portion 73 immediately upstream of the lip seal 46 and the leading edge 74 of the seal is formed diagonally upward toward the ear of the seal and the weir 16.

Because in their embodiment wherein the finishing chamber 19 is in the form of an upwardly directed helix the upstream portion 22 and downstream portion 23 are at different levels, a downwardly projecting transition is required from one side of the weir to the other; thus the brackets and lip seal from an elongated incline in the transition from the bottom to the side of the bracket. This is best illustrated in FIGURE 8 which is a cross section taken through the line 88 of FIGURE 5. The elongated incline 81 projects above the lip seal 46 during this transition.

The exact configuration of the lip seals is illustrated in FIGURE 9. As the weir is ordinarily coatedwith a resilient material such as polyurethane, it has been found that a more positive sealbetween the lip seals 91 and 92 is formed, if the lip seals are fabricated so that they are not under tension against the weir 93 they have dimen sions which would ordinarily make them project inwardly past the edge of the weir 93. This is illustrated in FIG- URE 9 by the fact that the lip seals 91,ancl 92 project inwardly past the edges of the weir 93 which is shown in phantom. By fabricating the lip seals in this manner, when the weir Works in its vertical direction against the seals there is formed a positive seal by virtue of the resiliency of the preferred polyurethane materials which are employed.

It is to be noted that the brackets which form the lip seal are conveniently made removable from the mill chamber so that when the lip seals wear they can be readily replaced by replacing the entire bracket assembly which may be either integrally molded from the polyurethane material or may be fabricated from metallic parts which are subsequently coated in a mold to give the desired configurations.

While particular embodiments of this invention have been shown and described, it is not intended to limit the same to the exact details of the construction set forth and it embraces such changes, modifications and equivalents of the parts and their formation and arrangement as come within the purview of the appended claims.

What is claimed is:

1. A vibratory finishing apparatus comprising a generally toroidal finishing bowl having a resilient lining in which a charge of parts to be finished and a finishing media are subjected to vibration, said apparatus being equipped with a retractable vertical weir for controlling both the motion of said charge and the unloading and separating of said parts and said media, said weir being sealed against the resilient lining of said apparatus by the provision of a resilient lip seal on the side wall and bottom of the interior chamber of said apparatus.

2. A vibratory finishing apparatus comprising a generally toroidal finishing bowl having a resilient lining in which a charge of parts to be finished and a finishing media are subjected to vibration, said apparatus being equipped with a retractable vertical weir for controlling both the motion of said charge and the unloading and separating of said parts and said media, said bowl including means for receiving said weir and allowing the same to be moved up or down in said bowl, and said weir being sealed with said bowl by a resilient lip seal at the bottom and sides of the interior of said bowl, said lip seal serving to resiliently bear against upstream and downstream sides of said weir.

3. A vibratory finishing apparatus comprising a generally toroidal finishing bowl having a resilient lining in which a charge of parts to be finished and a finishing media are subjected to vibration, said apparatus being equipped with a retractable vertical weir for controlling both the motion of said charge and the unloading and separating of said parts and said media, said bowl including means forming a channel for receiving said weir and allowing the same to be moved up or down in said bowl, said weir being sealed by a pair of resilient lip seals at the bottom of the interior of said bowl, said lip seals extending respectively across the upstream and downstream sides of said weir.

4. Apparatus as in claim 3 wherein said upstream seal is substantially U-shaped to provide a seal between the upstream side of said weir and the side walls and bottom of said bowl.

5. Apparatus as in claim 3 wherein the upper surfaces of said bottom lip seal each have a substantially concave surface terminating in said lip seals for providing a positive wiping seal against respective upstream and downstream sides of said weir.

6. A vibratory finishing apparatus comprising a generally toroidal finishing bowl having a resilient lining in which a charge of parts to be finished and a finishing media are subjected to vibration, said apparatus being equipped with a retractable dam for controlling both the motion of said charge and the unloading and separating of said parts and said media, said bowl including means for receiving said dam and allowing the: same to be moved up or down in said bowl, and said dam being sealed with said bowl by a resilient lip seal between at least the upstream side of said dam and the bottom of the interior of said bowl, said lip seal serving to resiliently bear against the upstream side of said dam.

7. A vibratory finishing apparatus comprising a generally toroidal finishing bowl having a resilient lining in which a charge of parts to be finished and a finishing media are subjected to vibration, said apparatus being equipped with a retractable dam for controlling both the motion of said charge and the unloading and separating of said parts and said media, said bowl including means for receiving said dam and allowing the same to be moved up or down in said bowl, and said dam being sealed with said bowl by resilient lip seal means between the bottom of the interior of said bowl and the upstream and downstream sides of said dam, said lip seal means serving to resiliently bear against the upstream and downstream sides of said darn.

8. A vibratory finishing apparatus comprising a generally toroidal finishing bowl having a resilient lining in which a charge of parts to be finished and a finishing media are subjected to vibration, said apparatus being equipped with a retractable vertical dam for controlling both the motion of said charge and the unloading and separating of said parts and said media, said bowl including means for receiving said dam and allowing the same to be moved up or down in said bowl, and said dam being sealed with said bowl by a resilient lip seal at the bottom of the interior of said bowl, said lip seal serving to resiliently bear against upstream and downstream sides of said dam.

References Cited UNITED STATES PATENTS HAROLD D. WHITEHEAD, Primary Examiner 

